1. Field of the Invention
The present invention relates to an apparatus and a method for providing information for decrypting content, and a program executed on an information processor, which are suitable for providing, for example, music content to a user. According to the present invention, the authentication capability of a portable terminal connected to a playback device is used to perform user authentication, thereby providing content with a sufficient reliability while only requiring a simple mechanism.
2. Description of the Related Art
In the art of providing a variety of content such as video, it is usual before providing the content to determine by performing user authentication whether or not a user who desires to obtain the content is an authorized user.
FIG. 7 is a block diagram of this type of content providing system, known as a satellite broadcasting system 1. In the satellite broadcasting system 1, satellite broadcast waves transmitted from a broadcast satellite 2 are received by a set-top box (STB) 3 to obtain video content.
The satellite broadcasting system 1 encrypts the content transmitted by the broadcast satellite 2 using a predetermined encryption key, and transmits the encrypted content, while modifying the encryption key at a predetermined timing. In the satellite broadcasting system 1, a card 4 having predetermined data recorded thereon is submitted to a user under a subscription contract. The card 4 is inserted in the set-top box 3 to access a certificate server 6 via a public line 5 such as a telephone line, so that the data recorded on the card 4 is transmitted to/from the certificate server 6 to authenticate the user. The set-top box 3 further receives a decryption key for a subscription program from a key delivery server 7 as a result of the user authentication, and uses the decryption key to decrypt the content. Therefore, the satellite broadcasting system 1 allows only authorized subscribers to utilize subscription content.
FIG. 8 is a block diagram of another type of personal identification system 11. In the personal identification system 11, a terminal device 12 accepts an ID, a password, a fingerprint, or the like, which is entered by a user, and transmits such information to a certificate server 14 over a network 13. The personal identification system 11 allows for personal identification at the certificate server 14, and allows for various services from a license server 15 as a result of identification. The personal identification system 11 may sometimes combine the certificate server 14 with the license server 15.
The satellite broadcasting system 1 requires a special structure necessary to authenticate the card, thereby increasing the complexity of the overall system. The satellite broadcasting system 1 further requires the certificate server 6 and the key delivery server 7 to authenticate a user and issue a key, thereby further increasing the complexity of the system configuration.
On the other hand, the personal identification system 11 described with reference to FIG. 8 requires a tamper-resistant mechanism because the terminal device 12 must obtain personal information necessary for verifying IDs, passwords, or the like, thereby increasing the complexity of the system configuration. Since the personal information is retained in the terminal device 12, it is necessary to provide a mechanism for preventing illegal use of the personal information, thereby increasing the complexity of the system configuration.